Since mobile communication terminals are affected by technical limitations such as small antenna size and environmental factors such as complex use environment and incomplete network coverage, users usually encounter the problem of poor call quality and communication quality. With the construction of 4G network, the same mobile communication terminal needs to simultaneously support various systems and various frequency bands such as 2G, 3G, 4G, wifi and Bluetooth. At this moment, it is very difficult to make the efficiency of an antenna very good, such that the problem of poor communication quality is comparatively serious. How to improve call performance and communication quality in a limited space of a mobile phone is an eternal pursue of antenna design engineers and radio-frequency engineers. As known by one skilled in the art, communication between a mobile communication terminal and a base station is completed through data interaction in an uplink and a downlink. Herein, the downlink generally refers to the link where the base station transmits signals and the mobile communication terminal receives the signals. The uplink generally refers to the link where a mobile phone transmits signals and the base station receives the signals. The influence of the uplink and downlink on communication quality is very critical. As found in studies, quite a lot of call block problems are caused by a reason that the propagation loss of uplink signals transmitted by the mobile phone is so great that the uplink signals cannot be correctly demodulated by the base station.